Re: the " 'official' point of view" expressed by kernelnewbies.orgregarding reiser4 inclusion

From: Jeff V. Merkey
Date: Mon Jul 31 2006 - 17:18:51 EST


Gregory Maxwell wrote:

On 7/31/06, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:

Its well accepted that reiserfs3 has some robustness problems in the
face of physical media errors. The structure of the file system and the
tree basis make it very hard to avoid such problems. XFS appears to have
managed to achieve both robustness and better data structures.

How reiser4 compares I've no idea.


Citation?

I ask because your clam differs from the only detailed research that
I'm aware of on the subject[1]. In figure 2 of the iron filesystems
paper that Ext3 is show to ignore a great number of data-loss inducing
failure conditions that Reiser3 detects an panics under.

Are you sure that you aren't commenting on cases where Reiser3 alerts
the user to a critical data condition (via a panic) which leads to a
trouble report while ext3 ignores the problem which suppresses the
trouble report from the user?

*1) http://www.cs.wisc.edu/adsl/Publications/iron-sosp05.pdf

Hi Gregory, Wikimedia Foundation and LKML?

How's Wikimania going. :-)

What he says is correct. I have seen some serious issues with reiserfs in terms of stability and
data corruption. Resier is however FASTER, but the statement is has robustness issues is accurate.
I was using reiserfs but we opted to make EXT3 the default for Solera appliances, even when using Suse 10
due to issues I have seen with data corruption and hard hangs on RAID 0 read/write sector errors. I have
stopped using it for local drives and based everything on EXT3. Not to say it won't get there eventually, but
file systems have to endure a lot of time in the field and deployment befor they are ready for prime time.

The Wikimedia appliances use Wolf Mountain, and I've tested it for about 4 months with few problems, but
I only use it for hosting the Cherokee Langauge Wikipedia. It's performance is several magnitudes better
than either EXT3 or ReiserFS. Despite this, for vertical wiki servers, its ok to go out with, folks can specifiy
whether they want appliances with EXT3, Reiser, or WMFS, but iit's a long way from being "cooked"
completely, though it does scale to 1 exabyte FS images.

Reiser does have issues still, and I hestitate to standardize on it until I stop seeing reports from the field about
corruption and failover issues.

Jeff

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